Runnin' ball - light pitting

[fyrfyter43]

I recently picked up a Lee .530 RB mold to go with a new rifle. This is the first time I've tried running ball in quite a few years, as I just wasn't shooting enough to worry about the high price of swaged balls.

Friday I tried casting some ball. I first cleaned the new mold with mineral spirits and smoked it with a candle. The first few came out wrinkled (before the mold warmed up) and went back into the pot. I cast around 100 balls, so I know the mold was warmed up, but all of the balls had some degree of pitting on the surface. About half of them were pretty bad and went back into the pot...the others still had some pitting, but not as bad. The pitting is worse towards the top of the ball (closest to the sprue plate).

All of the balls weighed between 224 - 227 grains. What do you think could be the problem? Too hot? Too cold?

Sorry the pictures aren't too great. The balls aren't as bad as they look in the pics, although this is one of the worst.

 

[bingo1952]

The metal may be just a tad on the cool side but I think that greasy soot from that candle you are using on your mould is your biggest problem. Casting bullets with greasy moulds is not a good idea. The soot from that candle looks good and goes on quicker and easier than a wooden matches soot will but dry soot is the key. If you dwell too long in any one spot with a candle the soot will continue to build in thickness. This is going off topic a little but greasy candle soot applied to a front sight will catch light and glare whereas dry match soot is perfectly flat in nature.

 

[Bob Riegl]

:wink: I don't think that the soot whether candle or butane lighter is the problem. The rainbow colors look to me as if the mold was cold when the bullet was cast. I usually let the Lee molds sit on the pot and through the first 6 away, if it's a Lyman mold I will sit the mold on an electric heater before starting to run ball. Then I may have to throw back a couple before the mold comes up to temperature.Clean your mold and re blacken with a butane lighter in addition---just to eliminate any dirt problems. Do you have a thermometer for your pot? That will let you know whether or no the lead is up to temp.I think you will be running ball happily the next time--let us know. :thumbsup:

 

[longcruise]

After 100 balls your mold would have come up to temp. If it's a temp problem, then its the lead temp that's too low. Another problem can be over lubricating the mold. Lube per the instructions, but be very sparing in your lube. Too much lube ends up migrating into the interior of the mold with results that look a lot like your pics.

Looks like a dirty mold to me. Try scrubbing with carb cleaner and a tooth brush and then smoke it with a wooden match. I often cast with lee molds without smoking them and have no problem.

It always seems to me that pure lead needs to run hotter than alloys or mixes like wheel weights.

The colors in the ball are suspicious and could indicate impurities in your lead. OTOH, they could be just reflections of the light sources around the room.

I'd throw em all back and start over.

What is your heat source?

 

[fyrfyter43]

The rainbow coloring is in the lead. I got the lead from Rotometals last week, and the ingots show the same coloring. I also have some of the same coloring on a few balls without any pitting.

I'll probably try casting some more later in the week. I think it might be the soot from the candle that's causing the pitting. That was my first thought when I saw it. I guess the first thing to try is cleaning up the mold and smoking it again with a wooden match. If I still have trouble, I'll increase my lead temp.

 

[fyrfyter43]

No, I don't have a thermometer. I guess I should pick one up.

I'm using a Lee Production Pot IV. I have the temp control set a little past 7.

 

[R.M.]

There's no law that says you have to smoke the mold. Try it nekid.

 

[mazo kid]

Is there any oxidation in the cavities?

 

[buckknife]

Never cast a ball or bullit in my life but im around iron castings.If it were a casting it looks to be slag,which needs skimed off the metal before its poured.Id reckon its the same with lead.Always keep the sprue full of hot metal from the time you start pouring the mold till its completly full.This will help avoid shrinks also. :v

 

[Zonie]

I don't know for sure but, to me those colors look like something is in the lead besides lead.

I've cast balls too cold and I've cast balls too hot but I've never seen pure lead (or even slight alloys of lead) make the red/blue colors I'm seeing in these pictures.

If there is some unknown alloy in the lead it could be a major reason why the balls are not casting like they should be.

 

[R.M.]

I've seen the colors in pure lead many times, but not every time. I have no idea what does it, but it seems to show up more-so with the purer leads.
My first though when I saw those pictures was that the melt needed to be fluxed, and it was crud showing up, but I believe he's using good clean lead from the foundry, and it shouldn't have much junk in it.

 

[paulvallandigham]

The marks I am seeing suggest wrinkles, rather than pits, and that indicates the lead is not hot enough. Do NOT expect those dials on your pot to be accurate. They rarely are. Get a thermometer to judge the temperature of your lead.

I believe that when you get the lead hot enough, and stop putting stuff other than soot in the mold, the colors will go away, as will the hint of wrinkles. You have to keep both the molten lead, and your mold hot enough to get good bullets or balls. At least your casting technique is apparently consistent, based on the close weight of the balls.

Oh, make a good sized "puddle " of lead on top of the sprue cutter, so that there is that extra heat to the mold as the ball cools. You will know when the ball is cooled enough to remove the sprue when you see a dimple form in the center of the sprue hole, and the "puddle" change color as it also cools down. It should take 5-10 seconds for that cooling to be complete on a ball that size.

Don't rush the casting process. Put the mold back up on the top rim of the pot for 5 seconds to reheat it, before pouring the next ball or bullet. I use that time to pick up the sprue, and slide it back into the pot. Others move the sprue aside to stack it for placing back in the pot when they need to feed more lead ingots or sticks to the pot to bring it back up to a healthy supply. Watch your thermometer any time you put new metal into the pot.

I found that putting the recently removed sprues back into the pot did very little to cool the molten lead, because the sprues were way over 100 degrees and too hot to handle with bare hands. Because they were already so hot, they didn't represent a big contrast to the temperature of the lead in the pot.

 

[ssettle]

You really need to get a thermometer. You need to know the temperature of your lead. I use the Lee pot also but I took the temperature sensor out and hooked a variac to it so I get better control on my melt. It works good for me.. It looks to me like your mould isn't venting like it should. Clean the vents with a brass brush. You may need to let the mould vent by not holding your dipper to tight to the sprue plate on the mould. Good luck SS :thumbsup:

 

[swedepie]

I have never molded ball or bullet. Just gathering lead for now and learning. What temp do you recommend for lead Balls?

 

[paulvallandigham]

pure lead melts at about 615 degrees F. For most casting, you want the temperature closer to 700 degrees F, and even higher if you are casting any alloys. It makes a difference if you are using a bottom pour pot, or using a dipper. Its difficult to keep the dipper hot for very long, even dipping it into the molten lead and waiting until the dipper is hot enough that the lead pours off it when you lift the dipper out. You have to hold your mold close. I found, with one single cavity mold, that I needed to actually tip the mold sideway so that the hole in the plate was at 90 degrees to vertical, then quickly lift the dipper up from the lead in the pot, put the spout into the hold, and then tip the two things up to vertical to make the pour so that I got a good cast.

I later opened the hole in the dipper's spout to increase the rate of the pour, and opened the hole in the cut-off plate to get more lead into the mold faster. Then, I got a bottom pour pot, and that eliminated a lot of problems I had been having with the open top pot, and the dipper. Provided I heated the mold up enough, the bottom pour pots put more hot lead into the mold faster, and produced much better balls and bullets in multi-cavity molds.

If you don't have a good scale to weight powder, buy one. You will want to weigh balls, or bullets to see how uniform your casting is, and to sort bullets by weight. Weighing balls and bullets is the only way I know to find those bullets with substantial air bubbles in the casting.

Wrinkles on the outside indicate that the lead or mold or both were too cold for the cast.

Frosted bullets or balls indicate the lead or mold, or both are too hot! BUT, I have never found any weigh variances or size difference with frosted balls. They shoot just fine. On that basis, I always advice casters to ERR on the side of making their lead too hot!

Lead pots use a theromocouple to measure temperatures. However, these devices corrode over time from the humidity that is present and attaches to the probes or ends when they are hot. The corrosion makes them inaccurate, and most casters find they have to ship the pots back to the company every five years or so, for overhauling, and new gauges. Its usually cheaper than buying a new pot! This advice applies if you cast a lot of bullets or balls, or if you live in and work in a particularly humid area. Using a separate thermometer will tell you when the dial temperature setting on the pot is way out of line with the actual temperature produced. And, it will tell you when its broken and needs to be replaced, or repaired and overhauled.

 

[fyrfyter43]

Paul, it's funny you mention your experience casting with a ladle. I’m starting that a ladle might work better for me.

I had a couple of hours this afternoon so I decided to try and figure out the problem I was having. I cleaned the mold up with brake cleaner, let it dry, and smoked it with a wooden match. I let my lead heat up for almost a full hour, so I know it was up to temp. Right before I started casting I fluxed with beeswax and skimmed off any dirt/dross. I set the mold on the edge of the pot to preheat it. Only the first 2 balls came out wrinkled. After that they looked good, except I still had the pitting. I cast about 30 balls - every one was pitted. Many were as bad as or worse than the one in the pics.

Next I turned the temp of the pot up to "high". I let it heat up for another 1/2 hour since I had put the pitted balls and sprues back in. I again heated the mold and started casting. The balls were still coming out pitted - just like the first 30.

I returned the balls and sprues to the pot and let them melt down for about 15 minutes. Then I grabbed my Lyman dipper and stuck it in the pot to heat up. I poured about 30 balls with the dipper. Most were wrinkled...the first few because I didn't warm the mold up. The rest because the bottom pour rod wouldn't let me get the dipper as deep into the lead as I would like, especially as I used more lead. Because I couldn't keep the dipper in the lead the spout started to clog up, not letting me pour as quickly. However, not a single ball was pitted!

Is there an easy way to temporarily plug up the bottom pour spout so I can try casting with the dipper instead of the bottom pour spout? Or does anybody have any idea why I might be getting this pitting when I use the bottom pour spout, and how I can fix it?

 

[bingo1952]

It sounds like you did all the right things so I would venture a guess that your pot has either a partialy clogged pour spout or the hole in the spout is too small especially if you got good balls out of the ladle. I can't get good minie balls out of a bottom pour pot and use a ladle.

 

[fyrfyter43]

I would venture a guess that your pot has either a partialy clogged pour spout or the hole in the spout is too small especially if you got good balls out of the ladle.

That's what I think too. I just cast 20 balls with the ladle - the first 8 went back into the pot, but the other 12 look great. All 12 were between 224 - 225 grains.

After that, I poured the rest of the lead off into my ingot mold using the bottom spout. It looked like there might have been some dirt in there. I'll take a look at the bottom spout tomorrow once it cools down. I'd be just as happy to find an easy way to block it off to make it easier to use a ladle. I seem to be more consistent with the ladle...I think I just get into a better pace.

 

[R.M.]

Are you stirring the melt up real good? And I mean real good. Stir it with a wood dowel and scrape the sides good. The carbon created is acting as a flux.
I'm thinking that you have crud getting through, and partially blocking the spout. All the crud should be floating on the top, where you can scrape it off.

 

[sproulman]

YOU GUYS REALLY KNOW YOUR STUFF ON HERE,LIKE GOING TO COLLEGE :hatsoff: